I kind of reluctant to publish this information... but I hope this would be useful especially to fellow Indonesian who too poor to afford the valuable internet. For a record I'm a loyal IM2 (ISP) customer for 2 years now. But somehow it is possible to lower the subscription cost from Rp. 125.000 ($14) / month into merely Rp. 5.000 ($ 0.6) / month.
How? first it's a GPRS modem based service (the one I owned but can be a 3G). It's a good idea to choose GPRS here. The following facts exposed how ridiculous the IM2 services is:
1. You buy initial SIM card for Rp 150.000 and ALL YOU GET is account. Yeah, the card is unable to make a call right? that's because its pulse (analogue to SMS pulse). The fact is you could use any regular CDMA card (for CDMA modem) just to dial #777 and login.
2. Account is NOT bound to anything but Indosat's billing system (a RADIUS based server), that means: Not your SIM card nor your modem will be used for identification.
At minimum you just need to buy a cheap CDMA modem, regular CDMA SIM card (starone is a good candidate) and get some accounts.